{"id":200,"date":"2007-02-14T00:47:25","date_gmt":"2007-02-14T05:47:25","guid":{"rendered":"http:\/\/crschmidt.net\/blog\/?p=200"},"modified":"2007-02-14T00:47:25","modified_gmt":"2007-02-14T05:47:25","slug":"from-data-to-map","status":"publish","type":"post","link":"https:\/\/crschmidt.net\/blog\/archives\/200\/from-data-to-map\/","title":{"rendered":"From Data To Map"},"content":{"rendered":"<p>Earlier this evening, <a href=\"http:\/\/nikolasco.livejournal.com\/372166.html\">Atrus<\/a> pointed out that DC has a bunch of cool data in their <a href=\"http:\/\/dcatlas.dcgis.dc.gov\/catalog\/search_predef.asp\">GIS Data Catalog<\/a>. I decided I would play with it a bit and see what I could come up with.<\/p>\n<p>I grabbed the <a href=\"http:\/\/dcatlas.dcgis.dc.gov\/catalog\/download.asp?downloadID=88\">Street Centerlines<\/a>, played with it in <a href=\"http:\/\/qgis.org\/\">QGIS<\/a> to do a bit of cartography, and then (eventually) got it exported to a MapServer .map file (which describes styling info). I was then able to set the file up in <a href=\"http:\/\/mapserver.gis.umn.edu\/\">MapServer<\/a>, serve it out to <a href=\"http:\/\/openlayers.org\/\">OpenLayers,<\/a> and then to stick <a href=\"http:\/\/labs.metacarta.com\/wms-c\/\">TileCache<\/a> in the mix. <a href=\"http:\/\/dc.freemap.in\/?lat=38.90984&#038;lon=-77.02769&#038;zoom=14&#038;layers=B0\">The result<\/a> isn&#8217;t the prettiest thing in the world, but it works.<br \/>\nAfter going through it once, I decided I&#8217;d go through it all again, to see how long it took.<\/p>\n<ul>\n<li>12:15AM: Open Firefox to <a href=\"http:\/\/dcatlas.dcgis.dc.gov\/catalog\/results.asp\">the DC Data Catalog<\/a> to find some data to map.<\/li>\n<li>12:16AM: Pick out <a href=\"http:\/\/dcatlas.dcgis.dc.gov\/catalog\/download.asp?downloadID=92\">Structures Polygons<\/a>.<\/li>\n<li>12:17AM: Download complete, open QGIS<\/li>\n<li>12:18AM: Open file in QGIS<\/li>\n<li>12:19AM: Save QGIS project file, save map file from project file<\/li>\n<li>12:20AM: Copy both shapefile and mapfile to server<\/li>\n<li>12:21AM: Tweak mapfile: adjust PNG output to not be interlaced (for TileCache usage), change background color<\/li>\n<li>12:22AM: Test mapfile in mapserv CGI. Find out I misspelled something, fix it.<\/li>\n<li>12:23AM: Edit TileCache config to add new layer information.<\/li>\n<li>12:24AM: Copy an existing tile URL, ensure that it works in TileCache with the different layer.<\/li>\n<li>12:25AM: Edit OpenLayers config to include additional layer<\/li>\n<li>12:26AM: Edit OpenLayers config to include layerswitcher.<\/li>\n<li>12:27AM: Marvel at <a href=\"http:\/\/dc.freemap.in\/?lat=38.90984&#038;lon=-77.02769&#038;zoom=14&#038;layers=0B\">the result<\/a><\/li>\n<\/ul>\n<p>In less than 15 minutes I was able to turn a dataset into a browsable, lazily cached web viewable data set, using qgis, OpenLayers, and TileCache. Not bad at all.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Earlier this evening, Atrus pointed out that DC has a bunch of cool data in their GIS Data Catalog. I decided I would play with it a bit and see what I could come up with. I grabbed the Street Centerlines, played with it in QGIS to do a bit of cartography, and then (eventually) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44,54,61,58],"tags":[],"class_list":["post-200","post","type-post","status-publish","format-standard","hentry","category-locality-and-space","category-openlayers","category-qgis","category-tilecache"],"_links":{"self":[{"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/posts\/200","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/comments?post=200"}],"version-history":[{"count":0,"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/posts\/200\/revisions"}],"wp:attachment":[{"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/media?parent=200"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/categories?post=200"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/crschmidt.net\/blog\/wp-json\/wp\/v2\/tags?post=200"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}